Stillavell e



JNITED STATES PATENT OFFICE.

STILLWELL I HARCOURT, OF CHICAGO, ILLINOIS, ASSIGNOB TO THE \V. V7. KIMBALL COMPANY, OF SAME PLACE.

PEANO=FORTE Acrton.

GPECIFICATION forming part of Letters Patent No. 384,254, dated June 12, 1888.

Application filed December S, 1887. Serial No. 257,339. (No model.)

To aZZ whom it may concern/.-

Be it known that l, STILLWELL R. HAR- COURT, a citizen of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented a new and useful I111- proveinent in liano-liorte Actions, of which the following is a specification.

This invention relates to a new method of rendering piano'forte actions quickly repeating under partial strokes of the key-such, for instance, as are imparted in trilling.

I accomplish the object soughtby combining a spring with the ham mcr-bntt and back catch or check as follows: One end of the spring is 1 secured in the hammerbutt, while the other end extends outward into such proximity to the back-catch as to ride upon the top of the latter at the conclusion of each key-stroke. By this means an elastic sustaining or lifting force is transmitted to the ham nicr-butt, which acts to prevent the hammer from falling entirely back, so long as the key remains de pressed. This will be better understood from the accompanying drawings, whcrein 2 Figure 1 is a side elevation of a piano-key and its action, showing the parts at rest. Fig. 2 is a like view of the action, showing theposition of the parts at the conclusion of a keystroke. Fig. 3 a partial section on the line 3 3 of Fig. 1.

In said drawings, A represents the hammer, a the butt thereof, B the string, C the jack, I) the back-catch, and E the baclccatch hunter, of an ordinary piano-forte action.

F is the spring by which my present improvement is secured. It is attached at one end to the hammer-butt in such manner as to transmit to the butt a lifting-power when its other end is raised. This attachment may con- 1,0 sist of a coil, j, in the spring, let into a recess,

in the butt, a pin, 71, passing through the butt and the coil, and the extremity '2' bearing upon the surface of the butt. The free end of the spring extends outward into the neighborhood of the back-catch, and is preferably bent upward, as atj, so that it may ride easily over the surface of the catch to the top thereof as the catch moves forward and the spring upward. This occurs at the conclusion of the downstroke of the key, the parts being then in the position shown at Fig. 2, with the hammer in the act of striking the wire. The spring now continues to bear on the catch until the key has been raised at least partially, and its action is to detain the hammer in the vicinity of the sounding-wire so long as the key is re ceiving the quickly-repeated partial strokes.

I prefer to let the intermediate portion of the spring rest in a groove, 6, in the banter in the manner illustrated, as the hunter thus acts to some extent to confine the movement of the spring to a single vertical plane. v

It will be noticed that in this invention the spring is not called into action until the key has nearly reached the bottom of its dip, so 6 that it has no tendency to harden the first part of the stroke. It is also very accessible for repairs or adjustment.

I claim 1. In a piano-forte action, the combination, 7@ with the hammer and the back-catch, of a spring, F, borne by the hammer and having contact with the catch at the latter part of the key-stroke, substantially as set forth.

2. In apiano-forte action, the combination, with the hammer, the butt,and the back-catch, of a spring, F, secured to the butt and contacting with the catch at the latter part of the stroke, substantially as set forth.

3. In a piano-forte action, the combination, with the hammer, the butt, the hunter, and the backcatch, of the spring secured to the butt resting upon the hunter and striking the catch, substantially as set forth.

STILIAVELL It. H ARICOURT.

\Vitnesses:

H. M. MUNDAY, JOHN W. llLIUNDAY. 

